Pwn20wnd has announced that the unc0ver jailbreak v2.1.0 is no longer in pre-release testing and has officially been released. Unc0ver supports jailbreaking iOS 11.0-11.4b3 (including betas).
Now that Cydia Substrate has been updated, jailbreakers are advised to install it for improved stability.
Make sure that you have the latest Cydia Substrate update to get the best possible experience with unc0ver.
Note: unc0ver v2.1.0 completely removes jailbreakd if you have Cydia Substrate.